How to unblock a toilet fast

A blocked toilet is one of the most common plumbing problems in the home. In this article, we’ll tell you everything you need to know about how to unblock a toilet if the water won’t go down the pan.

In 2016, the drain unblocking organisation Welsh Water told the BBC that the drain network is being used like a bin. The UK in fact spends tens of millions of pounds on drain unblocking services every year. Hopefully you won’t have to add to that statistic – here’s how to unclog a toilet, without – fingers crossed – having to get an emergency plumber.

How to unblock a toilet – flushing overview

When you flush the toilet, water flows from the cistern into the pan. The pan contains a bend or trap, which keeps a small body of water present. This acts as a barrier between your bathroom and the sewer, keeping bad smells from the drain out of your house. The shape of the trap also creates a siphon effect, helping to suck the effluent out of the pan. Most toilet blockages are located inside the pan, i.e., the porcelain component.

Tips and equipment for unblocking a toilet

There’s a few things you should think about before beginning this job, which will hopefully make it as bearable as possible.

  • Rubber gloves – These are pretty much the cardinal piece of equipment for this task. They’ll stop your hands from getting dirty. Plus, if you know what it is that’s blocking your toilet, such a nappy or toy, you can use them to simply reach in and grab it.
  • Ventilation – Make sure the area is well ventilated. Open the bathroom window to let plenty of fresh air in. Don’t forget, however, to close certain doors. Bad smells will travel throughout the house.
  • Old newspaper or towels – Newspaper is a cheap way of soaking up any accidental spills and can be disposed of easily (but don’t throw it down the toilet!) Towels can be used as something more robust, but you may wish to throw them away afterwards.
  • Old clothes – Depending on the severity of the blockage, you way want to don some clothes which you don’t mind getting dirty.
  • Hot water – Some of these strategies involve the use of hot water, so be careful not to scald yourself.
  • Chemicals – Some of these strategies involve the use of chemicals. Always read the label, and never mix chemicals. This could result in a dangerous chemical reaction.

Before we begin, don’t be tempted to keep flushing – especially if the pan is full close to the brim, and there is no sign of the contents disappearing. You may end up with very wet feet and a lot of regret!

How to unblock a toilet with a plunger

In order to unblock a toilet with a plunger, you’ll need one specifically designed for this purpose. Toilet plungers have an extension on the cup which ensures they form a good seal in the pan. A plunger without this cup – known as a sink plunger or a cup plunger – is intended for unblocking sinks, showers and baths.

  1. Make sure there’s water in the pan. For argument’s sake, we’ll assume that there is. However, if the water has drained away very slowly, you’ll need to top it up again. Pour some water in but don’t flush it. This is to ensure that the plunger cup is covered, and to prevent the ingestion of air.
  2. Place the plunger in the water. You should do this in such a way so that there as little air in the plunger as possible. That’s because you want to make sure the plunger is agitating the water. Any air inside will act as a cushion for the water and stop its movement from shifting the obstruction.
  3. Place the plunger over the hole. Make sure that it forms a seal over the hole. If this is difficult, try dousing the cup of the plunger in hot water. This should make it more malleable.
  4. Plunge carefully at first. Don’t be tempted to plunge as hard as you can at first. Any air inside the cup may cause a splash.
  5. Plunge! A combination of small, sharp plunges and forceful, vigorous ones should get the water moving and the blockage on its way out.
  6. Be patient. You may not get immediate results.

If it works, congratulations! You have successfully unblocked a toilet with a plunger.

How to unblock a toilet without a plunger

If you didn’t have any luck with a plunger, or you simply don’t have one, there are still loads of different ways to unblock your toilet. For starters, you can try it with the toilet brush. It won’t be as effective a good plunger, but it may be enough by itself to agitate the water to clear the blockage.

How to unblock a toilet with hot water

This method is best used when a toilet is partially blocked, as pouring water into a toilet that’s completely blocked will probably just make the pan overflow.

  1. Fill up a bucket with hot water from the sink or the bath. Never use boiling hot water from the kettle, as sudden changes in temperature can crack porcelain.
  2. Pour the water into pan. You’ll need to pour the water as hard as you can without making the pan overflow. The higher the point from which you can do this, the better. In theory, the force of the large volume of water should shift the obstruction. The warmth of the water may also help to loosen any fats that are causing the blockage.

How to unblock a toilet with a mop

You can use a mop and plastic bag in order to unblock a toilet. This method works roughly the same way as a plunger, by agitating the water. You should ideally have three or four carrier bags to do this method as cleanly as possible.

  1. Place a carrier bag over the mop head. Use the handles of the bag to tie it in place; alternatively, hold it in place with your other hand.
  2. Place the mop and bag in the water.
  3. Use sharp, brisk strokes to push water down the hole. The movement of water should move the blockage. Once again, be patient – it may take a dozen or two strokes before you get results. Don’t do it so hard that the bag breaks – you don’t want to be adding to the blockage.
  4. Let the bag drain. Once you’ve unblocked the toilet, let the bag drain. Most carrier bags, such as the ones you get in supermarkets, tend to have one or two small holes in the bottom. The bag will probably have filled up with some of the contents of the toilet.
  5. Dispose of the bag. Once it has drained, you can place one or two more carrier bags over it in order to take it off the mop head as hygienically as possible.
  6. Disinfect the mop.

How to unblock a toilet with caustic soda

Otherwise known by its chemical name of sodium hydroxide, caustic soda can be an extremely effective toilet unblocker. It is the active ingredient in many sink and drain unblockers, and is cheaply available from local DIY stores. It works using a combination of heat and chemistry. Mixing caustic soda water creates heat, which softens grease and fatty deposits. The caustic soda itself converts fat into glycerine and salts, which are water soluble and can be flushed away. This method assumes that the pan is empty but the toilet is blocked (i.e. the water is draining away very slowly).

  1. Health and safety. Caustic soda can be exceedingly dangerous if not used correctly. When unblocking a toilet with caustic soda, you should wear chemical-resistant gloves and eye protection, and mouth/nose protection to stop you from inhaling the fumes. Make sure the area in which you are working is well ventilated.
  2. Prepare the mixture. Slowly add approximately 1 kg (2.2 lb) of caustic soda to approximately 4.5 litres (1 gallon) of water in a bucket. The mixture will bubble and fume. Keep your face away from the fumes, taking care not to inhale them. Tip: Always add caustic soda, never the other way round. Adding water to caustic soda will create an extremely high amount of heat. Never pour caustic soda crystals straight into the pan – the crystals will solidify and make the blockage worse.
  3. Slowly pour the mixture into the pan.
  4. Put the toilet seat down.
  5. Leave it overnight, or as long as stated by the instructions.
  6. The next morning, pour one or two buckets of hot water down the toilet. The toilet should now hopefully be unblocked.

How to unblock a toilet with a clothes hanger

It is possible to unblock a toilet with a clothes hanger/coat hanger. A basic wire clothes hanger can be bent into the appropriate shape, however you should be verycareful not to scratch the porcelain of the pan.

  1. Bend the clothes hanger. Twist it out of its original shape until it is roughly straight. While leaving around a third of it to be used as a handle, bend the remaining two thirds into a curve which can be inserted into the hole. Bend the business end over itself in order to make it more rigid.
  2. Insert the wire into the hole. While following the shape of the bend, push your way forward to try to clear the path. Take care not to scratch the pan.


One of the most important things you can do to prevent a blocked toilet is to educate household members what shouldn’t go down the toilet, such as wet wipes, dental floss, tampons and condoms. These things should be carefully disposed of with general household waste, and never flushed down the loo. Putting a basic bathroom bin next to the toilet should eliminate the temptation to flush these things. You should also make sure that younger family members know not to put random objects and toys in the loo.

There are certain chemicals, such a paint, which should never be flushed down the toilet or even thrown away in the rubbish. Instead, you should take these to your local waste disposal facility. Some compounds, such as grease and wax, may solidify and create a blockage. Unwanted medicines and medical items should be taken to your pharmacist, GP or hospital; used syringes and needles should be placed in a medical sharps box.

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British taps: here’s why the hot & cold are separate

Ah, British taps. For most Brits, separate hot and cold taps (or faucets, if you’re visiting from the good old US of A) are a part of every day life. However, for many visitors to the UK, including those from continental Europe as well as America, they are simply baffling. Why on earth are they separate? How can you wash your hands comfortably in water that’s either scalding hot, or ice cold? In this article, we’ll go through the most common arguments.

1. British taps risk contaminating the mains

One of the most widespread explanations refers to the construction of British houses after the Second World War. British houses built after this period were typically equipped with a cold water storage cistern in the attic. One of the main purposes of this cistern is to supply the hot water cylinder.

Nowadays, such cisterns are subject to a number of strict regulations in order to protect the water from contamination. For example, they need to have a lid in order to prevent debris and rodents from getting inside, and they must have certain fittings which prevent the ingestion of insects (which could otherwise find their way inside via travelling up the overflow pipe).

However, these regulations weren’t always in place. Older cisterns often didn’t have a lid, and they were usually made out of galvanised steel, which would corrode. Insects, rodents and even errant birds in the loft space would occasionally find their way into the tank, drown, and contaminate the water – which would eventually be used as hot water for the taps. That’s why, in British homes, your family told you not to drink from the hot taps or the bathroom taps.

It is this risk of contamination which is frequently cited as the reason why British taps are separate. It is argued that, in mixer taps, the hot water – which cannot be guaranteed as safe to drink – would merge with cold water from the mains and contaminate it.

Flaws – the taps

However, there are a number of flaws with this argument. The cold water storage cistern usually supplies the cold water to the bathroom outlets as well as the hot. Thus, there wouldn’t be any contamination of the mains water when both hot and cold come from somewhere else.

Another reason against this explanation is the taps themselves. Many mixer taps have separate internal waterways, meaning that the hot and cold waters never come into contact with each other until they exit the tap, so there’s no chance they can mix. As for mixer taps which do blend the hot and cold water inside the tap body, they require non-return valves to be fitted to both the hot and cold supply pipes. Either way, there’s no chance for contamination of the mains.

The water pressure

The other argument against this explanation is the pressure difference between the hot and cold water. Cold water from the mains is at a much higher pressure than water from the hot water cylinder, which relies on gravity.

It is theoretically possible in a faulty mixer tap or a mixer tap without any non-return valves for hot water to be drawn back into the mains. However, what often happens in this situation is that the high pressure cold water displaces the low pressure hot water, and fills up the cold water cistern from its outlet pipe at the bottom. It’s a common complaint from residents who, after installing a new mixer valve, find that their cold water cistern overflows when they run the bath or take a shower. In other words, the hot and cold water should never be allowed to mix with the chance of the hot water flowing back into the mains regardless of possible contamination. That’s because when it does, it tends to make the cold water cistern overflow.

So while this argument has a logical premise, it doesn’t really stand up to scrutiny.

2. Tradition

So why are British taps separate then? The simplest explanation is probably the best one: tradition. Most British housing was built at least a hundred years ago. In fact, many properties are even older. This was a time when there was no running hot water, and certainly no central heating. Mixing valves didn’t exist, and there was no reason for them anyway: any taps or spouts were cold only. The only way to get hot water was to heat it in a pan or a kettle over a fire. Consequently, when domestic hot water systems were invented, they were added separately. Houses which were rebuilt after the war carried on this tradition.

So what about, for example, Germany, a country where mixer taps are in practically every bathroom? German houses don’t have cold water storage cisterns  – all taps including the hot ones are supplied by a mains-fed tank. This means that there is equal pressure on both hot and cold, so no chance of creating an overflowing water tank.

But perhaps the reason why German plumbers took so strongly to mixer taps may be because of the sheer destruction of German housing stock during the Second World War. After the war, one in five buildings were destroyed. In many cities, not a single house was spared. Thus, there came the opportunity not to carry on a tradition, but to start a new one.

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Fortic & Primatic cylinders: what’s the difference?

The hot water cylinder is one of the most important components in your home. Hot water cylinders come in different types as well as in different sizes. But what’s the difference between a fortic tank and a primatic tank?

The difference between these two tanks relate to two different design aspects. Two things they do have in common, though, is that they are both vented and low pressure. By vented, these means that they are open to atmospheric pressure. And by low pressure, this means that they are supplied by a storage cistern.

But what makes a fortic tank unique is that unlike a conventional hot water cylinder, a fortic tank has its own integrated cold water storage cistern, instead of having a separate cold water storage cistern in the loft.

Fortic cylinders are ideal for flats or smaller properties where it wouldn’t be practical or possible to install a bulky cold water storage cistern. You can also buy both direct and indirect fortic cylinders.

  • An indirect fortic cylinder contains an internal heat exchanger, which consists of a coil of copper pipework. Water heated by the boiler from the central heating circuit is pumped through this coil, heating the water in the cylinder indirectly.
  • A direct fortic cylinder does not contain a coil. The water is instead directly heated by two immersion heaters. One of these heaters is typically on a cheaper night tariff of electricity (Economy 7); the other is used as a heat boost during the day.

So, what’s a primatic cylinder? The answer lies in the heat exchanger. You see, in a typical indirect hot water cylinder – fortic or not – the heat exchanger consists of this coil of copper pipework we mentioned in earlier. Water in the coil and your radiators is supplied by a feed and expansion tank in the loft.

However, in a primatic cylinder, the cold water storage cistern not only supplies the cold water to be heated for the taps, it also supplies the water for your central heating. When the cylinder fills up, an air bubble is formed inside the heat exchanger. It is this air bubble which keeps the domestic hot water and the central heating water separate.

For this reason, primatic cylinders have serious disadvantages in comparison to cylinders with a coil and a feed and expansion tank in the loft. You can’t fit a shower pump to them, and most importantly, you can’t put any inhibitor chemicals inside the central heating in case the bubble is lost and the two bodies of water merge. The end result of the latter is rusty brown radiator water coming out of your hot taps, and shorter radiator life, since you can’t put any chemicals inside them to stop them from corroding.

So there you have it – that’s the difference between a fortic tank and a primatic tank. There is actually quite a lot of difference, albeit in very different respects. It’s actually possible to purchase hot water cylinders which are both fortic and primatic, although these are very expensive and much less frequently encountered.

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Emergency plumber: what to do & who to call

Need an emergency plumber? Whichever corner of the country you’re in – London, Manchester, Cornwall or Edinburgh – this handy guide will tell you how to find a 24/7 plumber, who to contact, and how to quickly stop a leak or a burst pipe before they arrive to fix it.

Contents – Emergency plumber

How to quickly stop a burst pipe or a leak

An emergency plumber can take anywhere from 30 minutes to a couple of hours to attend your property. If you’ve got a leak or a burst pipe spraying water everywhere in the house, you can still stop the problem from getting worse. The first thing to do is find your stopcock or stop tap. This is a valve which controls the supply of water to every outlet in your home. It’s usually made out of brass and looks a bit like a tap, except with a pipe at each end. You’ll normally find it under the kitchen sink. It can also be found on the mains pipe which rises all the way up into the loft. This pipe is known as the rising main, and supplies the cold water storage cistern.

Can’t find the stopcock near the kitchen sink? It may be in another cupboard, a pantry, or in a different room altogether. It may be under the floorboards in some older properties. In some cases, it may have been boarded over by a lazy kitchen fitter when installing a new kitchen. In communal accommodation such as flats, it may be in a cupboard in a shared hallway. Such a cupboard may also contain the stopcocks for other flats or apartments in the building.

To turn off the water, turn the handle of the stopcock clockwise until it stops. This will prevent the leak from continuing indefinitely.

If the water won’t stop

Shutting off the stopcock won’t stop the leak immediately. At the very least, there will still be residual water in the pipes. You can limit the amount of water that drains out through the leak by opening the kitchen cold tap.

Leaking radiator or leaking radiator pipe

If you’ve turned off the stopcock and the leak doesn’t subside at all, it’s because it isn’t directly on the mains pipework. If you have a combi boiler and a burst radiator or burst radiator pipe, the leak will continue until the radiator and any adjacent pipework are empty. Potentially, the entire contents of the central heating circuit may leak out – i.e, the water in every radiator.

If you don’t have a combi boiler, then the water in your radiators is probably supplied by a feed and expansion cistern. This is a small cistern in the loft which supplies the radiators with water. Turning off the mains will stop the cistern from filling, and the flow of water from the leak should eventually stop. However, once again, potentially the contents of all the radiators may leak out until it does.

Cold water pipe leaking

If you’ve turned off the mains but the leak is from a cold pipe and it won’t stop, this may be because of the cold water storage cistern in the loft. Even with the mains off, this cistern may still contain up to 50 gallons of water. You can stop this water from exiting via the leak by turning off the gate valve on the cold outlet pipe. This is usually situated close to the cistern in the loft. If you can’t access the loft, opening all the hot taps will empty the cold water cistern. Opening the cold taps in the bathroom will help drain it faster, unless they are fed by the mains.

Hot water pipe leaking

If you’ve turned off the mains but the leak is from a hot water pipe which isn’t part of your central heating – and isn’t slowing down, then this is once again due to the water remaining in the cold water storage cistern. Hot water leaves your hot water cylinder courtesy of gravity acting on the water in the cold storage cistern.

You can immediately stop a hot water pipe leak from getting worse by closing the gate valve on the cold supply pipe to the hot water cylinder. This is easily identifiable by a red wheel-shaped handle in your airing cupboard, on a pipe which is usually the lowest one connecting to the cylinder.

If this doesn’t work, then opening all the hot taps is guaranteed to empty the cistern. Opening the cold taps in the bathroom will help empty the cistern faster, unless once again, they are fed by the mains.

Before calling an emergency plumber – do you actually need one?

This is probably the most important question – is an emergency plumber actually necessary? Take for example, an overflowing toilet cistern. The toilet at this author’s home was once overflowing. Water was pouring out of the overflow pipe at the side of the house. A quick check in the cistern showed that the float had merely unscrewed itself from the arm of the ball valve. Simply screwing the ball valve back on the float arm solved the problem in a matter of seconds.

Of course, more complex and more serious problems may require an expert. Even if you have stopped the problem from getting worse, you may not have the time or the tools to fix it. And even if you can fix it yourself, it may be much more straightforward to get a professional to do it. Also, fixing it yourself may not necessarily save you money. For example, you may find yourself having to take unpaid time off work to deal with it.

At any rate, if you feel that your skills aren’t up to scratch or that you can’t diagnose the problem yourself, you are much better off calling an emergency plumber. And remember, there are some things which should only be done by qualified professionals, such as removing asbestos or working on gas appliances.

Work out who you’re going to call

Finding an emergency plumber can be very tricky. If you have time, ask family and friends for recommendations. Thanks to word of mouth advertising, a reliable plumber will never be short of work.

Emergency plumbers online

If this route doesn’t come up with any names, the next step is to search online. The Association of Plumbers and Heating Contractors (APHC) and CIPHE, the Chartered Institute of Plumbing and Heating Engineering, are trade bodies for the UK plumbing and heating industry, and they maintain a list of registered plumbers. You can check if there’s anyone local to you by entering your postcode.

An obvious port of call is the Yellow Pages, which you can find online as However, while the site encourages customer reviews, it is simply a business directory, and doesn’t do much by itself to vouch for a tradesman’s credentials.

Verification sites

The independent UK consumer magazine Which? has a “Trusted Trader” scheme which scrutinises tradesmen and endorses them with its logo if they pass their assessment. Another good place to turn is, which is an index of tradesmen vetted and monitored by the site. It also encourages consumers to leave a review of the contractor they have hired. It goes without saying that for an emergency boiler work, you need someone who is on the Gas Safe Register. You should keep an eye out for credentials provided by boiler makers themselves. That’s because some of them operate their own accreditation scheme.

Once you’ve got some possible names to call, do a bit of extra research, if your circumstances allow. Do they have a website or a Facebook page? While not every good plumber has the time to maintain a presence on social media (or the need, due to work via word of mouth), a plumber who takes pride in his work may share some photos of his recent projects, accompanied by positive reviews. You should also keep a close eye out for the reviews which the plumber would prefer that you didn’t read.

Write down the task

Before calling an emergency plumber, it’s a good idea to write down as much as you can about the problem. This will prevent you from forgetting anything on the phone. It will also help the plumber to prepare for the task effectively. Don’t forget to mention how long the problem has gone on for, as well as anything you have attempted in order to fix it.


If possible, it’s definitely worthwhile doing a bit of research before hiring an emergency plumber to tackle the issue. For example, if your old gravity-fed shower has stopped working, there are several modern replacement solutions available. While a good plumber will talk you through the different options and explain what is and isn’t possible based on your individual system, it is a good idea to enter this conversation with an idea of what you are looking for. The clearer your end goal is, the better the plumber will know how to meet your expectations.

Make the call

Once you’ve done these things, it’s time to start calling. Explain the issue and how you would like it to be resolved. While an emergency plumber may be able to give you a rough idea as to how much it will cost, he probably won’t be able to give you an exact price until he has seen for himself what is required. However, he will be able give you his hourly rate and initial call-out charge, and also an estimate as to the cost of parts and equipment. Plumbers also sometimes have set prices for certain tasks.

You should find out if the plumber has insurance, and if that insurance covers adjacent properties, such as your neighbours. You should also find out if the plumber guarantees their work, and if their guarantee is backed up with insurance. An insurance-backed guarantee means that their work is still covered, even if they go bust. Also, don’t forget to ask if they are a member of the aforementioned trade bodies.

Calling emergency plumbers

You should contact and compare at least three or four different plumbers. Ideally, you want them to come round and give you an exact quote. Of course, in an emergency, this probably isn’t possible. However, it’s important to do as much as you can to obtain a competitive price. That’s because there is no standard industry rate for plumbers. Also, try not to rush into anything. A good emergency plumber will understand that you may need a bit of time to think things through. You may also need to discuss things with other members of the household.

Getting the work done

Once you know which plumber to hire, you should make an agreement in writing as to what you are expecting. This agreement should ideally be in the form of a written contract. It should contain a clear description of the project, the agreed price (most likely the initial quote) and the rate. (For longer projects, this should also contain the start and finish dates.)

You should also agree on the payment method beforehand. You do not want to try to pay for the work on a credit or debit card only to find out that the plumber only accepts payment by bank transfer. Once the work has been completed, this could put both parties in an awkward situation, depending on your finances.

When the work has been completed, don’t forget to ask for a Work Completed Certificate. This may be necessary in order to demonstrate that the work complies with local building regulations. Good luck, and get ready to put the kettle on and get some biscuits out for the plumber!

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Overflow pipe/warning pipe – difference

Overflow pipes and warning pipes are key components of any cistern, such as those found in your loft. In the event of ball valve failure, they can prevent serious structural damage to a property, while alerting the occupant to a fault. But what actually is the difference between an overflow pipe and a warning pipe? Is there even a difference?

What is the difference between an overflow pipe and a warning pipe?

The answer to this question lies primarily on the size of the cistern on which the pipe is fitted. On cisterns with a capacity of less than 1000 litres, the overflow pipe and warning pipe are the same thing and have the same purpose: to discharge excess water safely while alerting the resident that a cistern is overflowing. On such cisterns, the water level should be set to at least 25 mm below the overflow/warning pipe. The overflow pipe itself should be:

  • At least 19mm in diameter
  • Fitted at a constant fall
  • With a discharge point that is clearly visible

However, cisterns with a capacity greater than 1000 litres but less than 5000 litres require two separate pipes: a warning pipe and an overflow pipe, each with their own purpose. As the name implies, the purpose of the warning pipe is merely to alert people to a fault and to an impending overflow. The warning pipe should have a diameter of at least 25 mm, and should be at least 25 mm above the water level. It is typically smaller than the overflow pipe, which should be capable of evacuating all of the excess water under maximum fault conditions. The purpose of the overflow pipe is not only to prevent structural damage but also to prevent the inlet valve from becoming submerged. It should be positioned at least 25 mm above the warning pipe.

At the point of exposure outside a building, the warning pipe should be positioned below the overflow pipe as per the position of the pipes in the cistern, making it clear which pipe is which.

Note that cisterns with a capacity greater than 5000 litres have different regulations. For example, an electric alarm can be fitted in lieu of a warning pipe.


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lockshield or a lockshield valve is a type of radiator valve. It connects a radiator to the return pipe to the boiler. It is one of two valves normally found on radiators, the other being the TRV (thermostatic radiator valve). A lockshield can easily be identified by its small white plastic cap. However, unlike a manual radiator valve (which also has a small white plastic cap), it cannot be adjusted without tools.

Lockshield valve overview

The purpose of a lockshield is to regulate the flow of water through a radiator. Water pumped through the central heating circuit by the boiler will take the path of least resistance when it returns to the the boiler via the return pipe. This means that, generally speaking, the further away from the boiler a radiator is, the less hot it will be, and the longer it will take to heat up.

By adjusting the lockshields accordingly, the occupant can set the radiators to heat up equally, so that the radiators heat up at the same rate and that the temperature in each room is equal. This act is known as balancing the radiators. Generally speaking, the further away a radiator is from the boiler, the more open the lockshield valve needs to be, and vice versa.

Lockshields are typically 15 mm compression fittings. They are available as angled or straight fittings. For a standard radiator with an inlet and an outlet at each side, this will mean angled for pipes coming out from the floorboards, and straight for pipes which run parallel to the floor.

As mentioned, a lockshield is easily identifiable by its small white plastic cap, underneath which is a two-sided spindle. Once the radiators are balanced, the lockshield no longer needs to be turned, as it should be considered locked in its place, with the plastic cap shielding it from further adjustment. Even if the cap is removed, however, the spindle can only be adjusted with a pair of pliers or an adjustable spanner.

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Toilet won’t flush: how to fix

Toilet won’t flush? There are several possible reasons why nothing happens when you pull the lever or push the button on your loo. In this article, we’ll explain the common faults and how they can be fixed.

Contents – toilet won’t flush

Toilet cistern overview

In order to understand why your toilet won’t flush and how you can fix it, you need to know a little about the components inside the cistern.

A typical British toilet uses a plastic siphon to draw water out of the cistern into the pan. Pulling the flush lever on a toilet raises a plastic diaphragm in the bell of the siphon. The diaphragm lifts a body of water up to the neck of the siphon, where it then spills over and down through the outlet. A siphon effect is created, and the rest of the water is drawn out of the cistern. While the plastic diaphragm is flexible enough to allow the moving water to pass by it, it is supported underneath by a plastic frame. This ensures it has the rigidity to lift the water above the water line in the cistern.

As for the filling of the toilet cistern, this is usually controlled by a ball valve. This uses the water level to open or close a valve by means of a plastic float. When the water level in the cistern falls, the valve is opened, replenishing the cistern with water for the next flush. In the event that the ball valve fails, an overflow pipe will allow the excess water to drain out of the cistern.

No water

If your toilet won’t flush, the very first thing to check is the contents of the cistern. Take the lid off and have a look inside – is there actually water in there? Take a look at the ball valve. Has the arm become jammed upwards? Gently moving the arm up and down may make the water flow again.

If the arm moves freely but the cistern does not refill, then the water supply to the cistern has become interrupted. There is usually an isolation valve on the supply pipe, which is operated by a blade-edge screwdriver. Double check that this is open – the notch in the screw on the valve should be in line with the pipe. If it’s closed and there’s no reason not to open it, give it a quarter turn with a screwdriver.

Toilet cisterns are either fed from the mains or from the cold water storage cistern in the loft. The cold water storage cistern may also supply other cold outlets in the bathroom. It will also supply the hot water cylinder.

Check the other bathroom cold taps – do they work? If several other water outlets don’t work – and the kitchen cold tap does – then this suggests that the cold water storage cistern is not filling up. If you are able to go up into the loft, then take a look inside the storage cistern – there is a good chance it will be empty. Has the ball valve got stuck? Try the same thing with this ball valve and move the arm up and down. If the storage cistern starts to fill up, you have solved the problem. However, you should consider replacing the ball valve, as it may seize up again in future.

Flush mechanism components

If cistern is full of water, the next thing to consider is the flush mechanism. The flush lever on the outside of the cistern is connected to the diaphragm inside the siphon via a small chain or piece of plastic. This link attaches to the siphon via a metal loop or hook. A faulty flush mechanism may very well be the case if the flush lever feels extremely light and makes a different sound. Check to see these components have become disconnected. If they have, reattaching them should solve the problem. If they are broken, you should be able to buy replacement parts from your local DIY store or plumber’s merchant.

Broken diaphragm

If the flush mechanism works, the next suspect is the diaphragm, which may be the case if the toilet will only flush in a certain way, depending on how hard or softly you pull the lever. A broken or punctured diaphragm cannot raise the water inside the siphon – the water simply passes through it. In this situation, the diaphragm must be replaced. If this isn’t possible, then you will need a new siphon. Either of these solutions means isolating and draining the cistern, disconnecting the pipework and unscrewing it from the wall.

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Equilibrium ball valve

An equilibrium ball valve is a type of ball valve which utilises the pressure of the incoming water to help close the valve.

Contents – equilibrium ball valve


In a standard ball valve, the incoming water enters the valve on one side of the washer only. As the water level in the cistern rises, the float raises the float arm, pushing a washer onto the valve seating, and closing the valve. Thus, the buoyancy of the float has to be sufficient enough to overcome the pressure of the incoming water.

This is where equilibrium ball valves do things differently. An equilibrium ball valve allows the incoming water to move to the other side of the washer. This keeps the water pressure equal on either side – in other words, in a state of equilibrium. By equalising the water pressure on either side of the washer, the upward force of the float only needs to be strong enough to raise the float arm. It does not need to overcome the pressure of the incoming water.

Equilibrium ball valves are useful in areas where the water pressure is very high, or for cisterns with a large diameter inlet pipe. They have also been used in order to overcome water hammer.


There are several different types of equilibrium ball valve in existence. Brass 1/2″ valves are available and are similar in appearance to Portsmouth pattern ball valves. Larger bores are also available, e.g. 1.5 inch, 2 inch, and the cost of these can run into hundreds of pounds each. However, these are obviously only used for very large cisterns, such as those in communal accommodation, e.g. a block of flats.

One of the main advantages of equilibrium ball valves is that because the float only has to lift the arm of the valve and not force it against the incoming water, the arm can be much lighter and more compact in comparison to traditional ball valves. This design concept is evident in the Torbeck line of float valves. These are are intended for use in toilet cisterns.

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Cold water tank overflowing – why?

Cold water tank overflowing? If there’s water dripping – or pouring from a pipe which points out of the house at loft level or from the eaves of the roof, then one of your cold water tanks is overflowing. This could be either the cold water storage cistern, which supplies the hot water cylinder and possibly the cold bathroom taps. Or, it could be the smaller feed and expansion cistern, which puts water into the central heating circuit. In this article, we’ll discuss what to do if the cold water storage cistern is overflowing.

Contents – cold water tank overflowing

Typical cause – a faulty ball valve

The most common reason for a cold water tank to overflow is a faulty ball valve. This valve controls the level of water in the cistern via a plastic float which sits on the surface of the water. As the water level in the cistern rises, the float pushes a washer onto the valve seating – a plastic nozzle inside the valve body. This stops the flow of water into the cistern.

Foreign objects, such as grit, dirt or limescale, or damage to either the valve seating or the washer may prevent a water tight seal. General wear and tear may split or chip the edges of the valve seating, and crack or split the washer. While these components are cheap to replace, it may be simpler to just replace the whole valve. Brand new Part 2 ball valves are cheap, reliable, and offer peace of mind that the problem is fixed.

The other cause – mixer valves

The cold water cistern can still overflow, even if the ball valve is working perfectly. This situation largely depends on the configuration of your plumbing system. Did you recently have a new mixer tap or shower with a mixer valve installed? If so, is it fed by the mains? This is very likely to be the cause of the problem. The high pressure mains water displaces the low pressure water from the hot water cylinder, pushing it back into the cold water cistern. If the cistern only overflows when a certain mixer tap or mixer shower is open, then this is almost certainly the cause. Alternatively, it may be caused by a pre-existing mixer tap or mixer shower developing an internal leak. The solution is to fit a non-return valve on the hot feed pipe to the tap or shower.


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Polytank feed and expansion tank (4 gallon/18 litre)

The Polytank feed and expansion tank is a feed and expansion tank produced by Polytank Group Ltd, the British manufacturer of water tanks and cisterns. As the name implies, the tank is designed to be used as a feed and expansion tank for open-vented central heating systems. It is suitable for new properties or as a replacement header tank on an existing installation. It has a capacity of 4 gallons / 18 litres.

Polytank feed and expansion tank

The tank is supplied with a snap-on lid, ensuring that dirt, insects and rodents cannot get inside, and a screened warning pipe fitting and washer, which also protects dirt and debris from entering the cistern via the overflow pipe.

You’ll also find a 15 mm Part 2 ball valve and a plastic float, and also a float valve backing plate – a small piece of plastic fitted to the ball valve shank, which protects the tank wall from the upward force of the float.

There’s also a insulation jacket for preventing heat loss, and a length of string for tying the insulation jacket around the tank. A service valve which would allow you to isolate the ball valve with a screw driver is unfortunately not included, however this can easily be purchased separately for a couple of pounds.

The tank is factory sealed, and all of the fittings are to be found inside the tank itself.

Note that while the capacity of the tank is listed as 4 gallons / 18 litres, the feed and expansion tank should never be full to this capacity when cold. The water level should be only slightly higher than the outlet at the bottom of the tank. This is so that the water in the central heating system has room to expand.


The Polytank 4 gallon/18 litre feed and expansion tank is WRAS approved, and is manufactured to BS4213:2004 and in ISO 9001:2008 approved factories.


Length: 480 mm
Width: 250 mm
Height: 320 mm
Weight: 2.2 kg

Where to buy

The Polytank 4 gallon/18 litre feed and expansion tank is available B&Q, which offers free delivery on orders over £50 and a click-and-collect service.

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